1900561 has 4 divisors (see below), whose sum is σ = 2046772. Its totient is φ = 1754352.

The previous prime is 1900553. The next prime is 1900571. The reversal of 1900561 is 1650091.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 690561 + 1210000 = 831^2 + 1100^2 .

It is a cyclic number.

It is not a de Polignac number, because 1900561 - 2³ = 1900553 is a prime.

It is a super-2 number, since 2×1900561² = 7224264229442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1900501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73086 + ... + 73111.

It is an arithmetic number, because the mean of its divisors is an integer number (511693).

2^1900561 is an apocalyptic number.

It is an amenable number.

1900561 is a deficient number, since it is larger than the sum of its proper divisors (146211).

1900561 is a wasteful number, since it uses less digits than its factorization.

1900561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146210.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 1900561 is about 1378.6083562782. The cubic root of 1900561 is about 123.8684218243.

The spelling of 1900561 in words is "one million, nine hundred thousand, five hundred sixty-one".